First-order effects

• Uploaders of borderline adult material face new enforcement risk as YouTube begins codifying what was previously an anything-goes norm, shifting moderation from ad-hoc takedowns to posted, predictable rules.
• Advertisers and mainstream partners gain a clearer map of acceptable content, lowering the perceived brand-safety risk that had kept big spenders cautious about the platform.

Second-order effects

• Competitors and would-be rivals can position around the gaps — the more YouTube polices its main site, the stronger the incentive for unmoderated or niche video hosts to absorb the spillover traffic.
• A formal rulebook creates demand for appeals, classification tooling, and human review, seeding the moderation-industrial complex (automated flagging plus contractor review) that platforms now treat as core infrastructure.

Third-order effects

• If the pattern holds, user-generated video converges on broadcast-style content standards — the frontier platform gradually adopts the liability posture of television, driven by advertiser money and regulator attention rather than any single law.
• The definition of 'acceptable' becomes a moving target negotiated between advertisers, advocacy groups, and creators — visible later in FTC complaints over kids' content and repeated loosening/tightening cycles — making policy volatility itself a structural feature of the industry.